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Category Archives for "Networking"

Cisco’s Nexus 9516 review: About line rate

Much ink has been spilled on the topic of what constitutes true “line rate,” and in the past we’ve advocated offering traffic at, and only at, 100.00 percent of theoretical line rate to determine if frame loss exists. However, the distinction between 99.99 percent (which we used in these tests) and 100.00 percent load is not all that meaningful, especially at higher Ethernet speeds, for a couple of reasons. First, Ethernet is inherently an asynchronous technology, meaning each device (in this case, the device under test and the test instrument) uses one or more of its own free-running clocks, without synchronization. Thus, throughput measurements may just be artifacts of minor differences in the speeds of clock chips, not descriptions of a system’s fabric capacity.To read this article in full or to leave a comment, please click here

Cisco’s Nexus 9516 review: About line rate

Much ink has been spilled on the topic of what constitutes true “line rate,” and in the past we’ve advocated offering traffic at, and only at, 100.00 percent of theoretical line rate to determine if frame loss exists. However, the distinction between 99.99 percent (which we used in these tests) and 100.00 percent load is not all that meaningful, especially at higher Ethernet speeds, for a couple of reasons. First, Ethernet is inherently an asynchronous technology, meaning each device (in this case, the device under test and the test instrument) uses one or more of its own free-running clocks, without synchronization. Thus, throughput measurements may just be artifacts of minor differences in the speeds of clock chips, not descriptions of a system’s fabric capacity.To read this article in full or to leave a comment, please click here

Cisco’s Nexus 9516 review: About line rate

Much ink has been spilled on the topic of what constitutes true “line rate,” and in the past we’ve advocated offering traffic at, and only at, 100.00 percent of theoretical line rate to determine if frame loss exists. However, the distinction between 99.99 percent (which we used in these tests) and 100.00 percent load is not all that meaningful, especially at higher Ethernet speeds, for a couple of reasons. First, Ethernet is inherently an asynchronous technology, meaning each device (in this case, the device under test and the test instrument) uses one or more of its own free-running clocks, without synchronization. Thus, throughput measurements may just be artifacts of minor differences in the speeds of clock chips, not descriptions of a system’s fabric capacity.To read this article in full or to leave a comment, please click here

Cisco Nexus 9516 review: How we did it

The device under test for this project was the Cisco Nexus 9516 data center core switch/router, a 16-slot chassis equipped with 1,024 50-gigabit Ethernet interfaces and two supervisor modules. Cisco equipped the switch with its N9K-X9732C-EX line cards, each of which offers 32, 64, or 128 ports of 100-, 50-, and 25-gigabit Ethernet capacity.The traffic generator/analyzer was Spirent TestCenter equipped with its 10/25/40/50/100G MX3 modules. The Spirent instrument has a measurement precision of +/- 2.5 nanoseconds.To read this article in full or to leave a comment, please click here

Cisco Nexus 9516 review: How we did it

The device under test for this project was the Cisco Nexus 9516 data center core switch/router, a 16-slot chassis equipped with 1,024 50-gigabit Ethernet interfaces and two supervisor modules. Cisco equipped the switch with its N9K-X9732C-EX line cards, each of which offers 32, 64, or 128 ports of 100-, 50-, and 25-gigabit Ethernet capacity.The traffic generator/analyzer was Spirent TestCenter equipped with its 10/25/40/50/100G MX3 modules. The Spirent instrument has a measurement precision of +/- 2.5 nanoseconds.To read this article in full or to leave a comment, please click here

Cisco Nexus 9516 data center switch aces a grueling high-density stress test

How many ports are enough at the core of the data center? How does 1,024 sound?That’s the configuration we used to assess Cisco Systems’ Nexus 9516 data center core switch. In this exclusive Clear Choice test, we assessed the Cisco data center core switch with more than 1,000 50G Ethernet ports. That makes this by far the largest 50G test, and for that matter the highest-density switch test, Network World has ever published.As its name suggests, the Nexus 9516 accepts up to 16 N9K-X9732C-EX line cards, built around Cisco’s leaf-and-spine engine (LSE) ASICs. These multi-speed chips can run at 100G rates, for up to 512 ports per chassis; 50G rates for up to 1,024 ports; or 25G rates for up to 2,048 ports. We picked the 50G rate, and partnered with test and measurement vendor Spirent Communications to fully load the switch’s control and data planes.To read this article in full or to leave a comment, please click here

Cisco Nexus 9516 data center switch aces a grueling high-density stress test

How many ports are enough at the core of the data center? How does 1,024 sound?That’s the configuration we used to assess Cisco Systems’ Nexus 9516 data center core switch. In this exclusive Clear Choice test, we assessed the Cisco data center core switch with more than 1,000 50G Ethernet ports. That makes this by far the largest 50G test, and for that matter the highest-density switch test, Network World has ever published.As its name suggests, the Nexus 9516 accepts up to 16 N9K-X9732C-EX line cards, built around Cisco’s leaf-and-spine engine (LSE) ASICs. These multi-speed chips can run at 100G rates, for up to 512 ports per chassis; 50G rates for up to 1,024 ports; or 25G rates for up to 2,048 ports. We picked the 50G rate, and partnered with test and measurement vendor Spirent Communications to fully load the switch’s control and data planes.To read this article in full or to leave a comment, please click here

Tapping big data to predict the future

Big data visualization tools are great for graphing past data to see patterns and trends, but future trends is a tougher nut to crack, since past performance is often no indicator of future actions. But graph database technology vendor Franz Inc. is doing just that with the latest version of its graph visualization software.Gruff 7.0 adds a new feature called a “time slider” that serves as a kind of time machine for temporal graph analytics. The new feature is intended to allow both novices and graph experts alike to visually build queries and explore connections as they develop over time and uncover hidden relationships within time-based data. To read this article in full or to leave a comment, please click here

Change in the Work Place: Attitude Can Be Everything

Change in the work place can be hard, unsettling, uncomfortable and… oh screw it… let’s just say it…. Change in the work place can just be down right scary when we are in the midst of it. 

I’m 52 so I’ve been through a lot of changes in my work environment over the years.  Since I’m a control freak it likely isn’t much of a shock that work changes like taking on a new job in a new company or new department aren’t the ones that I have the hardest time with.  I can see that this is because I feel like I’m the one who initiated the change in those situations.  I made the decision to move to that new company, job, or department.  I interviewed for it.  I felt it “called to me”.

But change in the work place is change in the work place.  Whether it is me initiating the change… or the change being “done to me”.  So why does a large re-organization in the same company feel scarier to me than me going to a new job at a new company?  They are both change.  Continue reading